Rigging a surface for game engine
So you want something like proportional edit, where you can grab any vertex and the neigbouring ones move along with it as well?

To do this, simply making sure the weightings (between the bones and the mesh) extend so that some vertices are controlled by multiple bones.

So this is the weight normally:


And this is it expanded:


If you expand all of them, then, although the neighbouring bones won't actually move, there will be the right effect (As far as I understand what you want):

In this case, I could probably have expanded the area of effect some more. And, you may notice you have to move the bone further to get the deflection you want. This is because the vertices you are moving are also influenced by the surrounding 8 bones, so will not move quite so much.